Scam and Fake Sites

When you try to open an unknown file extension and you use the Use the Web service to find the appropriate program option, if you happen to be redirected to a site called trustedsoftware.com, then your computer has been hijacked by a malicious program.

How did trustedsoftware.com hijack me?

If you've installed any free applications lately, they're probably the culprit. TrustedSoftware.com runs helpmeopen.com; if you look at the registry key
HKLM\SOFTWARE\MICROSOFT\WINDOWS\CURRENTVERSION\EXPLORER\ASSOCIATIONS
You'll notice that the values for Application,intl,and xmllookup have all been changed to point to http://www.helpmeopen.com/... which redirects to trustedsoftware.com

who owns helpmeopen.com?

True that they used a private registration, but if you look at the DNS servers, they're identical to trustedsoftware.com; most likely they knew that they would be using unethical means to drive traffic to their site and wanted to try to discourage legal recourse.

It could be that the actual owners are completely oblivious to the dirty deeds that drive traffic to their site and they are just being scammed by whoever does their marketing.

How to fix open file extension web service

Well, here is the correct registry key export, if you save the following to notepad with a .reg extention and import it into the registry, it will set the correct associations. If you've never worked with the registry or don't know what I'm talking about... then you really should become more familiar with the registry before tinkering with it.

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Associations]
"Application"="http://shell.windows.com/fileassoc/%04x/xml/redir.asp?Ext=%s"
"intl"="http://shell.windows.com/fileassoc/fileassoc.asp?LangID=%04x&Ext=%s"
"xmllookup"="http://shell.windows.com/fileassoc/fileassoc.asp?LangID=%04x&Ext=%s"